In the prior art, there have been numerous safety tilt mechanisms for limiting the potential damage experienced by outboard motors upon the boat encountering an underwater obstacle, such as a rock or log, during movement of the boat through a natural body of water. However, these mechanisms usually require that the outboard motor collide with an underwater obstacle directly and receive the impact of that collision in order for the outboard motor to be caused to tilt. Examples of such prior art mechanisms can be seen in, for example, U.S. Pat. Nos. 3,470,844; 3,570,443; 3,577,954; 3,648,645; 3,722,456; 3,859,952; and 3,952,687.
It is common knowledge that outboard motors are expensive pieces of equipment. As such, it is highly undesirable for an outboard motor to collide with an obstacle directly and receive the impact of that collision, since such impacts invariably result in a certain degree of damage being inflicted upon the outboard motor. Such damage may be to the mechanism for mounting the motor onto the boat, to the propeller, to one of the components of the propeller mounting housing protruding below the water line, or to the internal drive components mounted within the propeller mounting housing. Even the transom of a boat may be damaged in severe impact situations.
Heretofore, designs aimed at avoiding damaging contact of outboard motors with underwater obstacles have remained substantially undeveloped. However, notable attempts in this regard are the complex hull and transom altering designs disclosed by U.S. Pat. No. 5,238,432 (Renner). This patent relates to a Marine Drive Unit Impact Avoidance System, a device which, upon the impact arm of the invention encountering an underwater obstruction, provides for the drive unit to be lifted in a substantially vertical plane to clear the obstruction without any direct contact of the motor drive unit and the underwater obstruction. Renner broadly teaches a marine device unit impact avoidance system for boats of both the outboard and inboard/outboard types, which device is comprised, in the preferred embodiment disclosed, of two principal components, the first being an impact activating arm, pivotally mounted at one end to the bottom of the boat hull and at its opposite other end to the lower drive unit of the boat motor. The second main component of the preferred embodiment disclosed by Renner is comprised of a vertically moveable mounting means, which is adapted to have the boat motor mounted thereon so as to allow the motor to vertically slide, against the resistance of shock absorbers, upon an upwardly directed force generated by the impact activating arm hitting a rock, or other underwater obstruction. Both the impact activating arm and the motor mounting means are permanently mounted on the boat in a manner that prohibits the device from being readily transferred from one boat to another.
A secondary embodiment taught by the Renner patent is of more relevance to the present invention. In this embodiment, the device of the disclosed invention is shown in use with a conventional outboard motor, and is configured for mounting on the transom of the boat. That is, both of the two main components discussed above, being in this embodiment the engine mounting member and the impact activating arm, are mounted on the transom of the boat by way of a single base plate member. The motor in this embodiment also moves in a substantially vertical plane upon encountering a submerged obstacle as the boat progresses forwardly, and again, this alternate embodiment of the Renner patent is not readily interchangeable from one boat to another, as it requires breach of the transom's integrity and permanent modification to both the transom of the boat and to the housing of the motor. Thus, it not only lacks portability and interchangeability, but it is relatively complicated, expensive, and difficult to install. In addition, in both of the embodiments taught by the Renner patent, a boat is required to be physically removed from the water in order to perform the modifications necessary for mounting the device onto the boat.
It is a general object of the present invention to provide an outboard motor protection apparatus that protects an outboard motor from potentially damaging impact with underwater obstructions during passage of the boat through a body of water and, by reason of its relatively simple construction, overcomes the shortcomings of the prior art.
It is a further general object of the present invention to provide an outboard motor protection apparatus that can be quickly and easily installed and removed from a boat in situ, without breaching the integrity of the hull or transom of the boat and without requiring permanent modification to be made to such a boat.
It is yet another object of the present invention to provide an outboard motor protection apparatus that can be quickly and readily mounted and unmounted from the transom of a boat for use with an outboard motor without the use of hand tools or other subsidiary equipment.
It is a still further object of the present invention to provide an outboard motor protection apparatus that will not scratch or cause other incidental damage to the transom of a boat as a result of its installation thereon, use therewith, or removal therefrom.
It is an object of the present invention to provide an outboard motor protection apparatus that is preferably adjustable to various depths to protect the outboard motor from direct impact with obstacles located a varying depths below the surface of the water through which a boat moves.
It is another object of an alternate embodiment of the present invention to provide an outboard motor protection apparatus that will assist in preventing the propeller of an outboard motor from becoming entangled with underwater weeds.
There is thus provided, according to one aspect of the present invention, an outboard motor protection apparatus removably interposable between an outboard motor and a transom of a boat upon which the outboard motor is to be mounted. The outboard motor is of a conventional type having a downwardly depending propeller mounting housing terminating in a skeg portion. The mounting of the outboard motor on the transom of a boat is such as to allow for pivotal movement of the motor relative to the transom, about a first substantially horizontal tilt axis, between a drive configuration and a raised configuration. The outboard motor protection apparatus of the invention comprises means for removably mounting the apparatus onto the transom of the boat, with a base plate member extending downwardly in juxtaposed relation to a trailing face of the transom, and a leg member. The leg member has an upper end portion and a lower end portion, defining a longitudinal leg axis extending therebetween. The leg member is operatively positioned in leadingly adjacent relation to the skeg portion of the outboard motor, and it is mounted adjacent its upper end portion on the base plate member for pivotal movement of the leg member in a plane substantially transverse to the base plate member, about a second substantially horizontal tilt axis. The leg member moves pivotally between a rest position, whereat the leg axis is substantially vertically disposed, and a plurality of active positions, whereat the leg axis is removed from the rest position so as to place the leg member in operative contact with the outboard motor. The positioning and mounting of the leg member is such that, when it encounters an underwater obstruction as a result of the boat's forward motion through a body of water, it moves from the rest position to one of the plurality of active positions so as to cause the pivotal movement of the outboard motor from the drive configuration to the raised configuration. In this manner, the outboard motor avoids direct impact with the underwater obstruction, so as to be protected from damage through such impact.
In a preferred embodiment, the outboard motor protection apparatus is adapted to be removably mounted in overhanging relation over the transom of the boat. The means for removably mounting the apparatus onto the transom of the boat comprises an inverted "U"-shaped hook portion having a first arm formed by an upper extent of the base plate member, and a second arm formed by a downwardly projecting lip member. The lip member is connected to the first arm by a flange member adapted to overlie an upper free edge of the transom. The lip member is bifurcated to form two discrete laterally spaced lip member portions. The flange member and the lip member portions are together dimensioned and otherwise adapted to allow mounting clamps of the outboard motor to bear directly upon a leading face of the transom of the boat when the outboard motor is mounted upon the boat.
According to a further aspect of the invention, the bearing surfaces of the base plate member, the flange member, and the lip member portions, being those underside surfaces contacting the transom of the boat, preferably have a resilient cushioning layer applied thereover constructed from synthetic rubber. This synthetic rubber coating protects the transom from scratching and other incidental damage that might otherwise be caused by installing, using, or removing the outboard motor protection apparatus and lessens vibration that might otherwise be transferred from the base plate to the transom of the boat.
According to another aspect of the present invention, the leg member preferably has a horizontally disposed vortex blocking flange positioned in substantially surrounding relation thereto. This vortex blocking flange is located at a level on the leg member so as to be below the surface of the water when the apparatus is mounted on the transom of the boat in the manner indicated above, and the leg member is in its rest position. The vortex blocking flange act to assist in preventing the formation of whirlpools centered around the leg member as the leg passes through the water upon forward motion of the boat.
According to a further aspect of the invention the preferred embodiment further comprises a resilient strap member and a bumper member, having a motor mounting surface and a leg contact surface. The bumper member is removably mountable on the propeller mounting housing of the outboard motor in interposed relation between the outboard motor and the leg member when in use. Such mounting of the bumper member on the propeller mounting housing allows the bumper member to present its leg contact surface as a locus for controlled operative contact with the leg member upon the pivotal movement of the leg member from the rest position, as aforesaid. The bumper member preferably comprises a horizontally disposed finned portion which projects leadingly forward, in partially surrounding, non-contacting relation to the leg member, in its rest position. The resilient strap member is preferably connected to the bumper member at either end of its motor mounting surface so as to stretch over a trailing surface of the propeller mounting housing of the outboard motor, when the bumper member is mounted on the downwardly depending propeller mounting housing. The leg contact surface of the bumper member is preferably V-shaped.
According to another aspect of the invention, the upper end portion of the leg member is preferably formed by a discrete upper end segment, and the lower end portion of the leg member is preferably formed by a discrete lower end segment. The upper end and lower end segments are interconnected to one another by means of one or more discretely formed intermediate leg segments slidably mounted one within the other. An uppermost of the intermediate leg segments is slidably mounted within the upper end segment, and the lower end segment is slidably mounted within a lowermost of the intermediate leg segments. Taken together, the upper end segment, one or more of the intermediate leg segments, and the lower end segment form a telescopic leg member assembly.
According to yet a further aspect of the present invention, the outboard motor protection apparatus preferably further comprises a biasing means, such as a coil spring, interconnected between the upper and lower end segments of the leg member so as to bias the telescopic leg member toward a fully extended configuration.
According to a further aspect of the present invention, the outboard motor protection apparatus preferably further comprises a retracting means for controlled retraction of the lower end segment relative to the intermediate leg segments and the upper end segment of the telescopic leg member, against biasing by the biasing means. The retracting means preferably comprises a Bowden cable, and a control means. The Bowden cable of the retracting means has a first and a second end, the first end of which is operatively connected within the leg member to the lower end segment. The control means of the retracting means comprises a control handle, operatively connected to the second end of the Bowden cable, and a notched control panel which accepts the control handle in a plurality of different positions. As a result of the Bowden cable running between the control handle and the lower end segment of the leg member, each of the plurality of different positions of the control handle on the notched control panel corresponds to a different amount of retraction of the lower end segment of the leg member. In this manner, the outboard motor protection apparatus is adjustable to various depths, and is thereby able to protect the outboard motor from direct impact with obstacles located at varying depths below the surface of the water through which the boat is moving.
According to yet another aspect of the invention, the upper end segment, the intermediate leg segments, and the lower end segment are each preferably constructed from a non-resilient, rigid plastics material. Also preferably constructed of a non-resilient, rigid plastics material are the base plate member, the flange member, and the lip member portions. The bumper member is preferably constructed from a resilient plastics material having shock absorption qualities selected from the group consisting of rubber, synthetic rubber, nylon, and filled nylon.
The alternate embodiment of the invention differs from the preferred embodiment in that there is provided a leg member of constant length that reaches to a level below the skeg portion of the outboard motor, at which level two weed cutting blades are connected to the lower end portion. The two weed cutting blades operatively extend, one each, in opposite lateral directions toward a port side and a starboard side of the boat, in substantially horizontal, generally transverse axial relation to the longitudinal leg axis.